Hey, it's the post office. Entering the property is easy, leaving is like playing Russian Roulette. You never know what's waiting around that corner.
They have plenty of P.O. boxes here and some new self service kiosks.
However, the main area tends to get busy and it's not uncommon to wait 20 min in line. The staff are all pretty nice.
Come here after the DMV and it will seem like a breeze.